Pipe wrench



July 6 I926.

W. LEWIS PIPE WRENCH Filed N01. 12, 1923 WITNESSES:

' the center C, shown as a pin or rivet.

Patented July 6, 1925.

UNITE STATfi isms rarer sacs.

rIPE WRENCH.

Application filed. November 12, 1923. Serial No. 674,183.

The present invention relates to improvements in pipe wrenches and hasfor one of itsobjects the provision of a simple, efiective, cheap andsuperior type of wrench,

very light and strong and easily adjusted and held in position ready forimmediate use. i

The wrench consists of few parts so arranged as to give a limited amountof flexil bility' in the gripping jaws and the maxinum strengthconsistent therewith and a simple adjustment for any size of pipe fromthe smallest commercial size to the largest within its range of serviceas determined for the size and length of hand lever emv ployed. j

d Other objects of the invention will appear from the followingdescription, and

the invention will be claimed at the end 0 hereof.

In the following description reference will be made to the accompanyingdrawings forming part hereof and in which Figure 1 is a side elevation,partly in section, and with 'handleextension broken off to save room,showing the wrench as used in gripping a pipe, with a latch on to thehandle bar by which the jaws are quickly adjusted and held securely inplace.

Fig. 2 is a front elevation of Fig. 1 with the pipe omitted, and

Fig.3 is a side elevation, partly in section, and to' smaller scale, ofthe wrench shown in the other figures, fitted with inserted teeth and amodification of'holdfast adaptedfor closer rather than quickeradjustments. V

Referring to Figs. 1 and 2, H is the handle bar, a forging provided withteeth 1,

40 at its end to engage the pipe indicated at P. On the handle bar H, asliding sleeve or stirrup S is mounted to carry the bar B, and the latchL, provided with teeth 2, and made to engage or disengage mating teeth3, formed in the bar H. The bar B is attached to the stirrup S, as bypins or rivets 4, thus enclosing thehandlebar H, upon which it can beadjusted. The upper end of the bar B, carries the swinging-jaw J on Thejaw J is generally book-shaped and is stamped or milled out to provide agroove on its concave face. The walls of the groove embrace a part ofthe handle bar H and give it a firm lateral support, and the spacebetween the walls of the groove is utilized to enclose the spring 5which engages the notch 6, in the end of the bar B, and is held againstthe bottom of the groove in the jaw J by the-cross pin 7. Clearance isprovided between the sliding bar B and the bottom of the groove in theswinging jaw J, as at A, so that the spring 5 may tilt the jaw J(counter-clockwise as shown in a limited amount when no pipe is engagedand be held in readiness to take hold when pressed against a pipe anddriven back as far asthe clearance A permits. The spring thus located ishoused to be protected against damage in service, and, having a limitedamount of deflection, its durability is insured. The groove in theswinging jaw J provides a double working face with teeth 8, and thisdouble face is opposed by a single face on the handle bar, the describedfaces helping to properly position the wrench or the pipe and make thejaws more effective. The swinging jaw J is shown, Fig. 1, in its meanposition between stops, and in this position the gripping face whichcarries the teeth Sis a segment of a logarithmic spiral having aconstant obliquity to intersecting circular arcs from center C made toapproach but not to exceed the angle of friction between the teeth andthe pipe. This angle of; friction depends chiefly upon the sharpness ofthe teeth, and when they are kept in good working order,

it is believed an obliquity of 25 may safely be adopted. Of coursesmaller angles may be used, but they tend more to crush or distort thepipe than to turn it, and a wrench with gripping teeth easily renewed orsharpened canbe made in this way to actv at a large angle of obliquityand meet a longfelt want.

The logarithmic spiral, or curve of constant obliquity to intersectingcircular arcs struck from the center C may be approximated withsuificient accuracy for the purpose by a circular arc, and this movesparallelrto itself as the sleeve or stirrup S moves up or down to adjustfor different sizes of pipe.

The opposing jaw with teeth 1 may also be a circular arc to thesameradius as that of 8 but set at an angle thereto of some 15 orthereabouts to give a wider opening at. the mouth of the jaws than attheir throat and permit the jaw J to be swung back as far as theclearance A permits by pressing a pipe between the jaws. In this way thegripping jaws are made to engage a pipe of any size within the capacityof the wrench at approximately the same angle between tangents to thejaws at their points of contact and since the contact points may shiftwith the position of the pipe engaged whether large or small the wear onthe jaws becomes distributed over their entire length of face, insteadof being concentrated upon a limited arc of action a is generally thecase, greatly improving their durability.

Referring now to the latch L, Fig. 1, carried on the pin 9, in thestirrup S, it will be seen that this is held against the handle bar H bythe spring 10, anchored in the bar B, and that the. latch L has anextension 11 forming a trigger by which it may be disengaged from thehandle bar H. when so disengaged the stirrup S held between thumb andforefinger, can be moved quickly up or down to engage a pipe, and uponreleasing the trigger 11, the latch engages the handle bar H to anchorthe jaw J against any pressure applied. It will be seen that the spring10 is also protected and enclosed by the surrup S and that there are nodelicate parts in this wrench exposed to damage by rough usage.

In the modified form of wrench shown in Fig. 8, the swinging jaw J ismade to carry in its groove the toothed segment 12 held by pins orrivets 13, while the handle bar H carries upon its gripping end thebifurcated segment 1% pinned thereto as at 15. In this way the singleand double gripping faces are revers d and it is possible to keep thewrench in good working order by simply sharpening or renewing from timeto time the single toothed segment 12. On the double toothed segment 1%,the pressure is more direct. and the danger of slipping is so remotethat this part of the wrench may never require attention.

It will be understood that the pipe wrench as shown in its preferredconstruction, Figs. 1 and 2, must have longer gripping aws to cover thespacing of the notches which engage the latch L, than the jaws requiredwhere a closer adjustment is attainable as in Fig. 3. The modifiedconstruction therefore, may sometimes be preferred for its compactnesswhile the other will be preferred for its quicker adjustment, but ineither case I believe the inserted tooth segments have obviousadvantages in the conconstrnction and maintenance of a pipe wrench.

In Fig. 3, 16 is an adjusting worm mount ed on the sliding bar B andmeshing with rack teeth 17 on the handle bar H.

It will be obvious to those skilled in the art that modifications may bemade in details of construction and arrangement and mere matters of formwithout departing from the spirit of the invention which is not. limitedto such matters or otherwise than the prior art and the appended claimsmay require.

I claim:

1. A wrench having a groove provided in the concave face of its swingingjaw and extending throughout the length of the jaw, a pivot for theswinging jaw, a handle bar equipped with an opposing jaw and embraced bythe portions of the side walls of the groove that lie between the pivotand said opposing jaw, a sliding bar adjustably mounted on the handlebar and also embraced by said portions of the side walls and to the endof which the swinging jaw is pivoted. and a spring housed in saidportions of the side walls and interposed between the swinging jaw andsliding bar.

2. A wrench having a groove provided in the concave face of its swingingjaw and extending through the ends of the jaw, a handle bar equippedwith an opposing jaw and embraced by the side walls of the groove at theend portion of the handle bar, a slut ing bar embraced by said walls andto the end of which the swinging bar is pivoted, a stirrup embracing thehandle bar and sliding bar, a spring arranged in said groove andinterposed between the end of the sliding bar and the swinging jaw. andadjusting means interposed between the handle bar and the sliding bar.

lVILFR-ED LElVIS.

